A crystal of Green Fluorescent Protein (GFP) was placed under 13 atm. of Kr while mounted on the BL1-5AD goniometer in a standard crystallographic capillary. This was done by means of a system developed by M. Stowell. The energy was set to the Kr K fluorescence peak and a partial data set was collected. We were able to see two strong peaks in the Bijvoet-difference Patterson map. The GFP crystals were provided by Dr. Fan Yang from Prof. George Phillips' group at Rice University. Conventional techniques had been unsuccessful in producing GFP derivatives. We plan to pursue this project at the start of the next run.